If you know how to groom a horse for show, maybe you can offer bathing, body clipping and braiding services!
I HIGHLY recomend these! There are a couple of ladies/services I use regularly. On is a lady who makes sure to attend EVERY circuit, division, schooling or 4-H show. If there is a horse being shown or inspected or competing, or even just making a house call for a clean up. She pulls manes and tails, braids and bands. Hunter braids, dressage buttons, western bands, gaited or breed specialties (Friesans, saddle seat, Arabian, etc).
In the winter its impossible to find someone who can body clip and I'm more than willing to pay top dollar for someone who knows the difference between a 3/4 trace clip and an apron clip, and then coming back to maintain it.
If you're limited to whatever you can do on your farm; in my area raising chickens for organic eggs. It requires some hustling to connect with buyers at farmers markets, online local email lists/groups, but if you have time and motivation it can be lucrative.
This also may be a "Seattle" thing, but if you have goats you can always rent them out for property clearing. You set up a temporary secure fence and let them go to work. All natural environmentally friendly land clearing and you can get paid to sit and read while watching the goats.